Litter deposition dynamics, crown morphometry and fine root production of Eucalyptus urophylla hybrid clones under water stress

Abstract

The water deficit can be a limiting factor in the productivity of Eucalyptus spp. and the selection of adapted genotypes to these conditions is necessary. Therefore, understanding the adaptive capacity of genotypes in regions under water stress is crucial for the selection of genotypes. Thus, this work aimed to evaluate the litter deposition dynamics, crown development and fine root production of two hybrid clones of E. urophylla spp. The following were analyzed: (1) litter accumulation and its water retention capacity (CRH), (2) dendrometric growth and tree crown morphometry, and (3) biomass production of live and dead fine roots (0-25 and 25- 50 cm depth) during dry and rainy seasons. The litter deposition dynamics of clones was influenced by water seasonality, which was higher in the rainy season. For water retention capacity there were no differences. In turn, the genotypes showed adaptive differences, verified by the highest morphometric values of crown (ge, is and iev) in the dry season. Clone A had a higher significantly percentage of crown than clone B, whose leaf litter deposition was higher in the dry season. The highest production of fine root biomass was found in the 0-25 cm layer of the soil, being higher in clone B in both layers. So, the results open perspectives for further studies on the ecophysiology of the genetic materials of Eucalyptus spp and its applicability in forest genetic breeding for the selection of more productive and efficient genotypes for plantations in areas under water stress.